1. Field of the Invention
The present invention relates to a method and apparatus for placing corner boards, and stretch wrapping a load. In particular, the present invention is directed to automatically placing of corner boards on the vertical corners of a stacked lead having top and bottom caps, and wrapping stretch wrap packaging material around the lead while the corner boards are held in place.
2. Description of the Related Art
Products are often shipped and stored in cartons, which are stacked as a lead on a pallet to simplify handling of the cartons. The lead is commonly wrapped with stretch wrap packaging material to maintain the stacked configuration. To protect the lead during shipping and storage, particularly when the lead is fragile to indentation, top and bottom caps are provided on respective ends of the lead, and corner protectors are placed on the corners of the lead. Care must be taken so the lead is not damaged when positioning the protectors on the lead.
The positioning of the corner protectors is conventionally a time consuming and expensive process. If the process is performed manually, a corner protector must first be positioned and temporarily secured on each corner of the lead. The corner protector is temporarily secured using tape, straps, or hand wrap each corner of the load, a top cap is placed on the load. The load is then transported to a stretch wrapping machine for stretch wrapping.
Automated procedures also are available for positioning corner protectors on the corner of a load. These automated procedures generally require a top cap to be placed on the load after the corner protectors have been positioned, but before stretch wrapping has occurred.
In addition, these automated procedures generally store a number of preformed corner protectors vertically in a magazine, which can be difficult to load. The vertical magazine dispenses the preformed corner protector to a gripper placement device. In turn, the gripper placement device positions the preformed corner protector on a corner of the load by a series of positioning steps. It is recognized, however, that the preformed corner protectors may slip within the gripper placement device as it is removed from the vertical magazine, thereby creating a vertical misalignment between the corner protector and the corner.
Further, since the gripper placement device is used to maintain the corner protector in position until after stretch wrapping has been initiated, an overhead stretch wrapper is used to wrap the load. In such instances, it has been necessary to provide a separate gripper placement device for each corner of the load. The necessity of having four separate magazines and gripper placement devices is costly, both in available work space and intial investment expenses.
As such, there remains a need for an apparatus and method for reliably and efficiently placing corner boards on the corners of a load having top and bottom caps, and stretch wrapping the load with the corner boards in place, particularly in a way in which the load is not damaged during the application of the top and bottom caps, and the corner boards. Additionally, there remains a need for reducing the cost of an apparatus and method to place corner boards on a plurality of corners of a load.